Yes the four port is nice though I haven't used the eSATA yet, it performs as advertised. This was my first real large drive, prior to it I only had 250gig's or smaller. I like the drive, it's fast and not loud as some have said, at least mine isn't. The fan is quite as well.
I looked at enclosures at OWC before I bought it and the cost was about the same but the lacie seems to have more options. I've been using Lacie drives for a long time now, none have failed or given me any cause for concern, so I continue to have a good amount of confidence in their performance. I have a few OWC drives, and an Neptune enclosure that i used to use for swapping drives out. I would buy a drive only from OWC and pull the full one for storage and replace it with the new drive. With the 750gig which is closer to 700gig, I can probably extend my swaps for almost a year.
I do wish they would upgrade Silverkeeper backup software, it has served me well and i would like to bring it with me when I move to the next OS.